1. Field of the Invention
This invention relates to a needle shield to be coupled to a conventional dose metering syringe to hide a hypodermic needle from view of a patient to whom an injection is to be administered so as to minimize the anxiety that will be experienced by the patient prior to the injection. An additional automatic locking feature is provided that prevents the injection from being prematurely and/or accidentally administered until the needle hiding shield is first manipulated in a predetermined manner.
2. Background Art
Unique needle hiding shields to be coupled to a commercially available dose metering syringe were disclosed in our co-pending U.S. patent application Ser. No. 08/579,369 filed Dec. 27, 1995. This earlier patent application describes means by which to shield the hypodermic needle that is associated with a dose metering syringe from view of a patient (e.g. a child) so as to reduce the trauma and anxiety that will typically be experienced by the patient when the syringe is initially positioned at the targeted injection site. An injection is then administered by causing a medication cartridge housing to which the needle is connected to advance distally through the needle shield until the needle is unshielded to penetrate the patient's skin. At the conclusion of the injection, the medication cartridge housing is retracted proximally through the needle shield, whereby the needle is automatically reshielded.
It would be desirable to improve our earlier needle hiding shields by including an automatic locking feature. That is to say, the inadvertent or unintentional unshielding of the hypodermic needle prior to the injection could result in physical damage to or a contamination (i.e. loss of sterilization) of the needle. What is more, unshielding the needle after the injection has been administered could cause an accidental needle stick and the possible spread of disease. In either event, it would be advantageous to be able to lock the needle in a shielded condition and thereby prevent the accidental unshielding of the needle and the premature administration of an injection until the needle shield has first been manipulated in a precise and predetermined manner.